This invention relates to stackable plastic covers which allow a series of the covers to be stacked into a column and particularly to a stackable plastic cover for electric meter bases.
Electric meters, for many years, have used glass covers in the shape of a dome with a weld-on stainless steel rim to secure them to the meter base. The use of a plastic cover began about fifteen years ago and its design has remain basically unchanged since its inception. The prior art cover is molded from a clear high strength polycarbonate material and is designed to be of one piece construction. This is in contrast to the glass covers with their weld-on stainless steel rim. The shape of the plastic cover was patterned off the glass cover and stainless steel rim where the interior space was sized to fit over the internal meter components and the exterior height and. diameter of the flange were constrained to match with the mating sealing ring. In the original design of the prior art plastic cover, little attention was given to (1) the volume or envelope of the cover and the associated cost related to handling and shipping of the part, (2) interchangeability with all competitive meter bases and (3) minimizing the cost of manufacturing by a shorter mold cycle time and reduced weight of polycarbonate material. It was also a problem with the prior art covers to store a supply of the covers while they were waiting to be assembled with the meter bases since the covers were not designed, for nesting.